//
// Created by xili on 2024/8/3 10:10.
// Go big or go home.
//
#include <vector>
#include <unordered_map>
#include <unordered_set>

using namespace std;

class Solution {
public:
    bool uniqueOccurrences(vector<int> &arr) {
        unordered_map<int, int> ump;
        for (auto &item: arr) {
            ump[item]++;
        }
        unordered_set<int> ust;
        for (auto &item: ump) {
            ust.emplace(item.second);
        }
        return ust.size() == ump.size();
    }
};